[Libav-user] Criteria for h.264 key-frame detection

Carl Eugen Hoyos cehoyos at ag.or.at
Mon Oct 21 16:21:42 CEST 2013

Robert Krüger <krueger at ...> writes:

> If my debug output is correct, both contain no 
> B-slices/frames (I just noticed that) but they 
> do contain I-slices/frames. If I am not missing 
> something, those I-Frames should be valid random 
> access points then.

Do you mean you debugged the sample (with a stream 
analyzer) and you know that every I-frame is a 
random access point or would you just expect every 
I-frame in the sample being a random access point?

Testing the 720p sample, it appears to me that 
FFmpeg thinks the first random access point after 
the initial IDR frame is the 28th frame, a P-frame.
If FFmpeg is right (and the 27th frame is no random 
access point), how should the random access point 
be signaled?


> > Even better. Which commit are you talking about?

Iirc, fixed ticket with keyword "h264".

Carl Eugen

More information about the Libav-user mailing list